Building codes require emergency unit lighting fixtures for illumination of egress pathways, doorways, and the like to facilitate evacuation of a building during emergency conditions, such as when a main power supply to the building fails resulting in loss of usual illumination sources. Emergency unit fixtures provide a usable amount of light to enable evacuating persons to follow a preferred pathway out of the space being evacuated. Emergency unit fixtures or luminaires typically include a housing within which an emergency power supply, such as batteries, and circuitry are disposed for driving one or more lamps mounted to the exterior of the housing. In typical emergency unit luminaires, a pair of lamps are mounted to the top of the housing with each lamp being directed forward and to the side away from the housing. Such unit luminaires are often referred to as “frog eyes” and typically do not include a “legend” as exit signs do, thereby allowing use of emergency unit luminaires in locations inappropriate for exit signs.
Existing luminaires typically include either fixed optical assemblies or movable optical assemblies. Generally, a housing for mounting a fixed optical assembly has a different design and construction than a housing for mounting a movable optical assembly. In each type of emergency unit luminaire, the housing functions to mount optical assemblies, as well as to contain a source of emergency power supply along with necessary circuitry for operation and testing of the luminaire. Existing luminaire housings made of polymeric materials are often subject to material “creep” or sag due to the weight of a power supply, such as a battery, that is intended to be supported by the housing. Additionally, existing luminaires are time consuming to install and difficult to maintain because of fasteners that require tools for assembly and disassembly of the luminaire.
One existing unit luminaire includes external lamping mounted on a luminaire housing and aimed to direct light into a space in order to facilitate evacuation of the space when an emergency arises. Another existing emergency unit luminaire includes movable optical assemblies mounted to each end of the luminaire housing. Yet another existing device includes movable lighting assemblies operable within a combination emergency unit/exit sign. These existing movable optical assemblies are capable of swiveling or other motion, providing a single degree of freedom so that light from the optical assemblies may be directed toward desired locations.
Despite the existence of numerous commercially available emergency unit luminaires, there remain needs for a luminaire housing that is usable with both fixed and movable optical assemblies, configured to transfer at least the weight of a contained power source to a structure to which the housing is mounted, and easily installed without the use of tools and capable of ready disassembly for maintenance.